This is an optional CRC Aluminum Vertical Shock Tower Mount Set, and is intended for use with 1/10 and 1/12 pan cars. Popular on some 10th scale oval cars, these Aluminum Shock Tower Mounts allow you to vertically mount your carbon fiber shock tower to your chassis. They also work well for mounting mini servos, (such as the JR 3650), flat in 12th scale and 10th scale pan cars.